Sri Kirtan Sohila Sahib

Siri Kirtan Sohila Sahib

After traveling for many years and showing the people of the world the path to God, Guru Nanak Dev Ji came to a land near the banks of the Ravi River. This Land belonged to a wealthy man named Krori Mal who donated this entire land to Guru Nanak Dev Ji. The land was renamed to Kartarpur. Guru Nanak Dev Ji spent the later years of his life here in Kartarpur along with Bhai Lehna Ji. One afternoon, while staying in Kartarpur, Bhai Lehna Ji was giving Guru Nanak Dev Ji a massage. What did Bhai Lehna Ji see?
When he first started the massage Guru Nanak Sahib Ji was fine. He had no marks or cuts on his body, but now out of nowhere Guru Ji’s feet were bleeding. There were cuts in the feet as if they had walked over some prickles or something sharp.
Bhai Lehna Ji was shocked! He asked, “Guru Ji, you are sitting here yet how come your feet have started to bleed? How come there are cuts in your feet as if you have walked over something sharp?”
Guru Nanak Dev Ji said that there is a Sikh who is milking goats out in the field. Call that Sikh here and then I will give you the answer to your question. Guru Ji sent another Sikh to call the Sikh in the fields. When the messenger reached the fields the Sikh was reading the Bani of Kirtan Sohila while he was milking the goats. The messenger told the Sikh that Guru Ji was calling him.
The Sikh came and bowed to Guru Ji. Guru Nanak Dev Ji then told the Sikh, “Whenever anybody reads the Bani that you were reciting (Kirtan Sohila), I am always present there. While you were walking around in the fields reading Kirtan Sohila, I was walking behind you listening to the Bani. I didn’t let a single cut come on to your body; instead I took the cuts for you.”
The Sikh asked Guru Ji for forgiveness and asked what he should do now.
Guru Ji told him that Kirtan Sohila Bani should be read at night time before going to sleep. First you should wash your hands, feet, and face and then read the Bani with full concentration. If you do this, then I will sit by that person’s side and listen.
From this moment on, Kirtan Sohila started to be read at night time. Kirtan Sohila is a very short Bani, but some people are so lazy that they go to sleep without reading it. It’s not like Sukhmani Saheb which is very long. It is only a few small shabads.
If someone reads this Bani before going to sleep then they will not have any nightmares during the night. If you die during your sleep you will not become a ghost or evil spirit in your next life. Guru Ji will look after you.
This is Guru Ji’s Hukam, “That person who reads Kirtan Sohila before going to sleep will be close to me.”
While reading this Bani with concentration you should think in your mind that Guru Ji is sitting by listening to me reading the Bani. This Bani is comprised of 5 shabads; 3 from Guru Nanak Dev Ji and one each by the fourth and fifth Gurus.
Even Bhai Gurdas Ji writes that we should read Kirtan Sohila before going to sleep:
"They sing the Sodar in the evening and heartily associate with one another. Having recited the Sohila and made supplication at night they distribute sacred food (prasad)."

Source: http://www.searchsikhism.com/sohila.html